We have a grey water tank-the boat was built with it. The sinks and shower drain into it and then we have a large hand pump to pump it overboard
. (Guess this totally overides the purpose of the tank
is that I am always worried about putting something in that will smell, even though it doesn't, and I don't really like to have pump it out frequently.
The big plus
is that I end up with only one seacock for all of my drains and it is above the water line. Simple and safe.
As for your water tank problem, we have a similar situation. We do not feel comfortable using our tanks
for drinking water
but our two main watertanks are fiberglassed in to the hull
and kind of make a watertight bulkhead at the waterline and we don't want to tear these out. We are researching two different options. 1) line the original tanks with bladder bags or 2) add a third tank and have two different fresh water systems. One for potable water and one for dish washing
, showers etc.